The 8 - 12Ám infrared bandpass filter is used in many applications including infrared tracking (also known as infrared homing). Infrared homing is a passive system in which heat generated by the target is detected and homed on. Typically used in the anti-aircraft role to track the heat of jet engines. In the case of passive missile guidance systems, missiles which use infrared seeking are often referred to as "heat-seekers". Many objects such as vehicle engines and aircraft generate and retain heat, and as such, are especially noticeable in the infrared wavelengths of light compared to objects in the background. Early infrared seekers were most effective in detecting infrared radiation with shorter wavelengths, such as the 4.2Ám emissions of the carbon dioxide efflux of a jet engine. Modern infrared seekers operate in the 8 - 12Ám wavelength range, which is absorbed least by the atmosphere. For example, generally longer wavelength infrared (LWIR) 8 - 12Ám will suffer less signal transfer than shorter wavelength IR (SWIR) in haze and fog. Contact REFLEX Analytical to discuss your requirement. Available in a 1.0" diameter. Custom components are encouraged and quoted upon request.